Over the years, the increased demand for hydrocarbon products has resulted in expanded production, storage and handling of not only crude oils but various distillates. Several activities involved in the production, storage and handling of such products occurs in or near bodies of water. For example, crude oil may be drilled off shore, and transportation of the crude may be carried out by pipeline or ocean-going vessels. As a result of this increased activity, the likelihood of accidental spilling of petroleum-based products into various bodies of water has increased. Such inadvertent spills, can and do occur frequently. Further, on rare occasions, excessive amounts of petroleum-based products or oils can be discharged. These incidences have had well-documented devastating effects on the environment. They have caused long-lasting and even permanent damage to property and the surrounding ecosystem.
In recent years, increased emphasis has been placed on the preservation of the environment. In this regard, efforts have been directed to attending quickly to and containing spills which can be hazardous to the environment. Controlling, neutralizing and recovering contaminating and oily discharges have become an international concern.
Several approaches have been suggested for ameliorating the devastating effects of oil contamination. For example, U.S. Pat. No. 4,011,175 discloses using comminuted demoisturized mixtures containing perlite, clays and fibrous fillers. The comminution is preferably carried out with a hammer mill. The resultant granules are described as loose, fibrous materials which are oleophilic, hydrophobic and floatable on water for selective absorption and stabilization of hydrocarbons in a hydrocarbon-water system.
U.S. Pat. No. 4,072,794 discloses oil adsorbents containing natural fibers such as coconut husk or grass fibers treated with a paraffin wax emulsion and dried. The oil adsorbent is then treated with a latex material and cured. The natural fibers which have been subjected to a combination of treatments with paraffin and latex, are used as oil adsorbents in the form of mats, belts, or lumps.
U.S. Pat. No. 4,070,287 discloses the use of blends of polymeric and cellulosic fibers bound into a web or mat-like structure or retained in a net for removing oils from aqueous systems.
U.S. Pat. No. 3,960,722 oil adsorbents prepared from polyethylene resins and calcium. The mixture is introduced into oil-containing systems as a foam which is preferably shaped into a network of some sort such as a sheet or extruded as a rope.
More recently, U.S. Pat. No. 4,874,528 discloses methods for treating dispersions of oleophilic liquids and water. The methods include well known methods of separation as, for example settling, decantation, centrifugation and flotation.
Additional and various method are still needed for oil recovery. In particular, it is desirable to increase the dispersibility of the adsorbents in the contaminated aqueous systems and to enhance the amounts of oil which can be recovered per unit of sorbent.
It is, therefore, an object of the present invention to provide improved oil separation techniques by improving the dispersal of the sorbents and providing sorbents with increased oil gathering capacity.
Other and further objects of the present invention will be set forth in the following description, and its scope will be pointed out in the appended claims.